Hi there!
I actually have a problem. I have a proyect that is based in an Arduino that "reads" the tones that the mobile send, when you press a key. The idea was to use a DTMF decoder and a Arduino to decode it and, for example, open a door. But then I read that the actual smartphones, didnt have the DTMF signal system. Any ideas about how I can decode the tones of the keyboard?
For example, if I connect a modem to the decoder, and the decoder to arduino, and I call the number attached to modem, with a smartphone, and I press, for example, 123#, the decoder would decode it? (If the signal come from the smartphone)
One more thing, I dont want to make an app that comunicates the arduino with the phone, I want it without apps, to be without installing enything.
Thanks!
-MadScientist_J
MadScientist_J:
But then I read that the actual smartphones, didnt have the DTMF signal system.
What you read does not relate to your problem. The phone, smart or otherwise, should be able to send DTMF tones to the other end.
I would do a Google search for Arduino DTMF to see if someone else has solved the decoding problem already.
Use a HT9170 DTMF Decoder IC
I have already used the MT8870DE, for the decoding, using the circuit that goes in the datasheet, and it goes bad. So I google it, and I read that the DTMF signal are only for the analog ones, that digital phones, like smartphones, didn't use it.
MadScientist_J:
I have already used the MT8870DE, for the decoding, using the circuit that goes in the datasheet, and it goes bad. So I google it, and I read that the DTMF signal are only for the analog ones, that digital phones, like smartphones, didn't use it.
Well, they do, but the caller has to configure the phone to send DTMF tones. By default, they don't send DTMF.
For example, in my Galaxy S III, I go to Keypad -> (Menu) -> Call Settings -> Ringtones and keypad tones -> [check] Keytones
That will send DMTF codes with each key pressed. Since I am using the stock Android dialer, that setting will be in the same place in most Android device. I know that for most Symbian phones DTMF codes are enabled by default. For iPhones I have no idea if it is possible or where to configure it, since I don't own one nor I plan to.
Plan B. all you need is a phone and a VOIP box , plus an Arduino.
use phone call the phone number associate with VOIP box, then you will hear voice prompt, please key in password. once password is successfully entered. IVR (interactive voice response) menu is starting. please push "1" or say "open door" (Speech recognition) to open the door. please push "2"...
sample setup;-
Add Plan B as title.
I might hijack the thread, so let me release it.
Some newer phone might have problem to send out correct DTMF tone;
The one might have problem:
Blackberry
iPhone
Android 4.0/Ice Cream (Samsung Galaxy S II)
The phones are not affected:
Android 2.3/Gingerbread (Samsung Galaxy S II, Samsung Tab)
Normal land lines phone.
Same phone Samsung Galaxy S II is working on Android 2.3 but not Android 4.0.
Test your setup at normal land lines phone might be smart move.